Wash the potatoes (no need to peel) and chop finely.
Wash, trim and chop the spring onions into small slices.
Chop the asparagus into chunks.
Melt the butter in a medium size saucepan, then add the chopped spring onions and potatoes and cook on a low light for 4-5 minutes, stirring occasionally.
Add the asparagus, boiling water and the lemon juice.
Crumble over the stock cubes and season with the pepper and a little salt.
Bring to the boil, cover and simmer for 20 minutes until tender.
Liquidise, add the crème fraîche, warm through and serve.